Medical Definition of Red blood cells. Red blood cells: The blood cells that carry oxygen. Red cells contain hemoglobin and it is the hemoglobin which permits them to transport oxygen (and carbon dioxide). Hemoglobin, aside from being a transport molecule, is a pigment. It gives the cells their red color (and their name).
Alexander Milne Calder (August 23, 1846 â June 4, 1923) was a Scottish American sculptor best known for the architectural sculpture of Philadelphia City Hall. Both his son, Alexander Stirling Calder, and grandson, Alexander Sandy Calder, became significant sculptors in the 20th century.
Alexander was born around July 20, 356 B.C., in Pella, which was the administrative capital of Macedonia. His father was often away, conquering neighboring territories and putting down revolts. Alexander showed great aptitude as a child and one of his tutors was Aristotle, the famous Greek philosopher.